Bijan Parsia wrote:
> Thanks for the pointers. I don't have much to say that I've not already
> said. The issues you discuss vis-a-vis XMP seem more political than
> technical. Clearly, there is a requirement for extensibility. Beyond
> that, it's a bit hard to determine what the actual technical
> requirements are (no surprise, really). I wonder if aligning XMP with
> some RDFa profile would make sense.
The political and the technical are hard to distinguish though.
From what I know, somewhere around 2000, Adobe engineers were looking
for an extensible metadata framework that could be mapped to a GUI
reliably, without external configuration.
So they looked at RDF as it existed and said, "ah, RDF literals are kind
of like a hash, rdf:Seq, rdf:Bag, and rdf:Alt can be mapped to familiar
programming structures and UIs, let's just create a subset that only
allows those."
So it's a bizarre sort of subset; not of the syntax, but of the model.
It leans heavily on literals and blank nodes.
The spec is now effectively frozen by Adobe, which has a ton of legacy
issues that explain why they have no interest in turning it over to a
proper standards organization, or otherwise changing it.
Hence, the technical problems are closely connected to the political.
> Actually, I think there's a lot of milage to be gotten out of being less
> free and easy.
Which I guess aligns with periodic discussions of what has been called
"RDF Lite."
> One problem we faced at UMD with some of our tools is
> that they were *too* open and flexible. Photostuff, for example, would
> build forms for "person" from all the ontologies you loaded. So you got
> these HUGE forms with dozens of fields. And all you wanted to do was
> mark up the photo with the fact that it was a photo of your niece.
Norm Walsh had started to work on a cool web app for photo metadata. In
that case, the UI gets configured.
<http://norman.walsh.name/2006/09/13/photodata>
Bruce